These unassuming lighthouses have seen the first reading of the Pledge of Allegiance, the first wireless transmission, and more than one mystery.

North America's first frozen mummified remains of an ice age steppe bison, the 36,000 year-old mummy named "Blue Babe."

The collection includes seven one-of-a-kind automobiles, vintage fashion, and more.

A hulking remnant of Alaska's industrial gold mining boom in the 1920s.

The sculpture's largest spire points directly toward the North Star.

This frozen tunnel in central Alaska is both an engineering feat and a valuable climate classroom.

This gravelly, dangerous highway is the only road in the United States that leads to the Arctic Ocean.

The northernmost truck stop in the United States.

The stickered marker pinpoints where the only maintained road in the United States crosses into the polar region.

Mind-blowing carvings and fantasy ice scenes grace the largest year-round ice environment in the world.

A striking 12th-century-style castle built on the edge of a cliff.

An Iron Age hillfort rooted in Arthurian legend was made famous by musician Peter Gabriel.

This memorial to World War II's fallen airmen shows us the movements of the stars that once guided them.

Follow the original medieval paths that wind through this intriguing section of the city.

From Nunavut to Tierra del Fuego, you won't find any lighthouse higher than this one.

A magnificent, reportedly haunted mansion built for a composer by Spiritualists.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

Every weekend, people gather here for a brief chance to see their loved ones on the other side of the United States–Mexico border.

It's just another skyscraper, but it's shaped like '90s cell phone.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

A colossal floating restaurant built to look like a ancient Chinese imperial palace.

These tiered rice paddies were carved into the hillsides 2,000 years ago.

The remains of an abandoned air force hospital located on a redeveloped Air Force base.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.